1. Field of the Invention
Embodiments of the present invention relate to Controller Area Network (CAN or CAN bus) circuits and to automatic termination apparatus and methods.
2. Discussion of Related Art
The Controller Area Network (CAN) is a network bus standard that allows several devices, or nodes, to communicate with each other on a CAN bus in an ad hoc (e.g., point-to-point) manner. If the CAN bus is not properly terminated, signals transmitted by each device on the bus are subject to noise distortions and data corruption caused by signal reflections. Typically, resistors (e.g., 120 ohm resistors) are placed at each end of the bus to reduce or eliminate the signal reflections. A terminating resistor is conventionally included in a modular plug, which is installed in a complementary receptacle, or jack, on a node at one end of the bus. Thus, two terminating plugs are typically used for each CAN bus. One such plug is a terminating resistance package for RJ45 ports, part number 0W04161, sold by American Power Conversion Corporation of Kingston, R.I., the assignee of the present disclosure.